Chemical Imaging Method Research Articles

High-Throughput Raman Chemical Imaging for Rapid Evaluation of Food Safety and Quality

Abstract. High-throughput macro-scale Raman chemical imaging was realized on a newly developed line-scan hyperspectral system. The system utilizes a custom-designed 785 nm line laser with maximum power of 5 W as an excitation source. A 24 cm × 1 mm excitation line is normally projected on the sample surface using a 45° dichroic beamsplitter. A detection module consisting of a dispersive imaging spectrograph and a CCD camera is used to acquire Raman signals along the laser line. A motorized positioning table moves the samples transversely through the laser line, and hyperspectral data are obtained using a pushbroom method. System software was developed using LabVIEW to fulfill various functions such as parameter setting, data transfer, and image processing. The system covers a Raman shift range of -691.5 to 2841.2 cm-1 with a spectral resolution of 14 cm-1. The system can collect spatial information requiring either large instantaneous field of view (e.g., 23 cm) or high spatial resolution (e.g., 0.07 mm). The system performance was demonstrated by an example application for authenticating flour. The system acquired a 320 × 250 × 1024 hypercube (80,000 spectra) from three powder samples placed in three Petri dishes (two with a diameter of 47 mm and the other 90 mm) in 9 min. Azodicarbonamide particles mixed in unbleached flour can be detected based on the chemical image generated using a simple image classification method. The method and system for high-throughput macro-scale Raman chemical imaging is promising to inspect other food and agricultural products for safety and quality evaluation.

Comparison of different MR fat quantification methods at 3.0 T in a phantom study

Objective To investigate the value of MR imaging methods for the quantification of fat content in a customized lipid phantom at 3.0 T. Methods Eleven homogeneous fat-water phantoms (50 ml) with fat volume percentages from 0 to 100% were constructed with reference to Bernard's methods. Fat fractions of the lipid phantom were acquired using water selective saturation (WS), fat selective saturation (FS), in- and out-of-phase imaging (IOP), iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) gradient echo imaging and IDEAL Quant imaging methods on a 3.0 T MRI system. For statistical comparisons, paired-sample t test, Pearson correlation test, and Bland-Altman maps were applied. Results Evaluated fat fractions acquired by WS, IDEAL Gradient echo imaging and IDEAL Quant were (49.6±28.8)%, (46.0±28.4)%,(51.0±32.0)%,the result has no significant difference with the true fat contents(t values were -0.186, -2.218, 2.713;P values were 0.856, 0.051, 0.055). Evaluated fat fractions acquired by FS, corrected algorithm and IOP were (64.2±26.7)%, (58.9±31.9)% and (45.3±32.3)%, these three kinds of methods have significant difference with the true fat contents (t values were 5.168, 4.273, -6.441;P<0.01). All the chemical shift imaging methods correlated with the true phantom model fat fractions, r values were 0.977(FS), 0.978 (corrected algorithm), 0.982 (WS), 0.99 8(IOP), 0.993 (IDEAL Gradient echo imaging), 0.999 (IDEAL Quant) (all P<0.01). Each method's 95% confidence interval of the mean difference acquired by Bland-Altman map was WS (-14.7% to 13.8%), FS (-3.6% to 32.0%), corrected algorithm (-4.6% to 22.5%), IOP(-9.4% to 0.0%), IDEAL gradient echo imaging (-15.9% to 7.8%), IDEAL Quant(-2.0% to 4.0%). IDEAL Quant had the best correlation and confidence with the true fat fraction. Conclusions Chemical shift imaging methods (IOP, IDEAL Gradient echo imaging, IDEAL Quant) can acquire more accurate fat quantification results than chemical saturation imaging methods (FS, Corrected algorithm, WS) in a customized lipid phantom at 3.0 T. IDEAL Quant can acquire the best fat quantification result compared with the other imaging methods. Key words: Magnetic resonance imaging; Fat quantification; Phantom model

Investigation of protein distribution in solid lipid particles and its impact on protein release using coherent anti-Stokes Raman scattering microscopy

The aim of this study was to gain new insights into protein distribution in solid lipid microparticles (SLMs) and subsequent release mechanisms using a novel label-free chemical imaging method, coherent anti-Stokes Raman scattering (CARS) microscopy. Lysozyme-loaded SLMs were prepared using different lipids with lysozyme incorporated either as an aqueous solution or as a solid powder. Lysozyme distribution in SLMs was investigated using CARS microscopy with supportive structural analysis using electron microscopy. The release of lysozyme from SLMs was investigated in a medium simulating the conditions in the human duodenum. Both preparation method and lipid excipient affected the lysozyme distribution and release from SLMs. Lysozyme resided in a hollow core within the SLMs when incorporated as an aqueous solution. In contrast, lysozyme incorporated as a solid was embedded in clusters in the solid lipid matrix, which required full lipolysis of the entire matrix to release lysozyme completely. Therefore, SLMs with lysozyme incorporated in an aqueous solution released lysozyme much faster than with lysozyme incorporated as a solid. In conclusion, CARS microscopy was an efficient and non-destructive method for elucidating the distribution of lysozyme in SLMs. The interpretation of protein distribution and release during lipolysis enabled elucidation of protein release mechanisms. In future, CARS microscopy analysis could facilitate development of a wide range of protein–lipid matrices with tailor-made controlled release properties.

Lanthanide ion (III) complexes of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraaminophosphonate for dual biosensing of pH with chemical exchange saturation transfer (CEST) and biosensor imaging of redundant deviation in shifts (BIRDS).

Relaxivity-based magnetic resonance of phosphonated ligands chelated with gadolinium (Gd(3+)) shows promise for pH imaging. However instead of monitoring the paramagnetic effect of lanthanide complexes on the relaxivity of water protons, biosensor (or molecular) imaging with magnetic resonance is also possible by detecting either the nonexchangeable or the exchangeable protons on the lanthanide complexes themselves. The nonexchangeable protons (e.g. -CHx, where 3 ≥ x ≥ 1) are detected using a three-dimensional chemical shift imaging method called biosensor imaging of redundant deviation in shifts (BIRDS), whereas the exchangeable protons (e.g. -OH or -NHy , where 2 ≥ y ≥ 1) are measured with chemical exchange saturation transfer (CEST) contrast. Here we tested the feasibility of BIRDS and CEST for pH imaging of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraaminophosphonate (DOTA-4AmP(8-)) chelated with thulium (Tm(3+) ) and ytterbium (Yb(3+)). BIRDS and CEST experiments show that both complexes are responsive to pH and temperature changes. Higher pH and temperature sensitivities are obtained with BIRDS for either complex when using the chemical shift difference between two proton resonances vs using the chemical shift of a single proton resonance, thereby eliminating the need to use water resonance as reference. While CEST contrast for both agents is linearly dependent on pH within a relatively large range (i.e. 6.3-7.9), much stronger CEST contrast is obtained with YbDOTA-4AmP(5-) than with TmDOTA-4AmP(5-). In addition, we demonstrate the prospect of using BIRDS to calibrate CEST as new platform for quantitative pH imaging.

Mo1172 Effect of Long-Term Alcohol Intake on Pancreatic Fat Content in Humans -Characteristics of Alcohol-Induced Pancreatic Steatosis

Background: Long-term alcohol intake has always been regarded as one of the major causes of chronic pancreatitis (CP). However, 5%-10% of chronic alcoholics ever develop CP. And no successful animal model of CP could be induced by alcohol alone. Our previous study and other accumulating animal studies showed that long-term alcohol administration led to pancreatic steatosis. Unfortunately, it is still unclear whether there is alcohol-induced pancreatic steatosis in humans and how to make a diagnosis of it. At present, chemical shift magnetic resonance imaging, a reliable, noninvasive, and quantitative method, is found useful for identifying pancreatic steatosis in the clinical practice by determining tissue fat content in vivo. Objective: to find out the characteristics of alcohol-induced pancreatic steatosis in humans so as to help make the diagnosis of it. Methods: 137 healthy male volunteers and 131 alcoholics aged 20~70 years with a normal body mass index were recruited into this study. The healthy volunteers were included as the normal control without any digestive system symptom or a long history of drinking. The alcoholics were defined as the drinkers with an alcohol intake of > 80 g / day, a duration of >5 years, and abstinence from alcohol within 2 years. All of them received magnetic resonance scanning in the epigastric region by using double-echo chemical shift magnetic resonance technique. Their pancreatic fat content was determined. Results: In each age group, pancreatic fat content of alcoholics was about twice as that of healthy control, p 0.05). CV among the three regions did not show any difference between alcoholics younger than 40 years and their corresponding healthy controls. In the age groups older than 40 years, CV of pancreatic fat fraction of alcoholics significantly increased compared with their corresponding control by approximately 45%, p 80 g ethanol /day, duration >5 years) including the abstainers, 2) pancreatic fat content higher than 4.2%, 8.0% in alcoholics younger and older than 50 years, respectively, 3)unevenly distributed fat in the pancreas of the drinkers older than 40 years. Those characteristics may help us to make a diagnostic criteria of the disease.

Chemical imaging of the sulfur-induced deactivation of Cu/ZnO catalyst bodies

The effects of sulfur poisoning on the water–gas shift (WGS) activity of industrial Cu/ZnO/Al2O3 catalyst bodies have been studied. The samples were characterized using chemical imaging methods, including XRD-CT, XAFS mapping, and XRF, in order to understand the process by which accelerated sulfur poisoning leads to catalyst deactivation. After ∼90h on stream, all catalysts exhibited reduced activity; the higher the H2S concentration, the greater the extent of deactivation. Non-invasive XRD-CT measurements performed on intact samples recovered from the reactor revealed the formation of sulfide phases, including sphalerite (β-ZnS) and crystalline CuS, Cu2S, and CuSO4 phases. These sulfide phases were distributed predominantly as a graduated corona around the sample edge reaching ∼1.5mm thick for experiments performed in the highest concentration of 500ppm H2S. XAFS mapping, which is particularly sensitive to the local coordination environment around the element being probed, confirmed the presence of mixed Cu/Zn–O/S coordination environments and that the core of the sample remained sulfur-free. A combination of XRD-CT and XRF revealed that CuS appeared to be mobile under reaction conditions resulting in the redistribution of Cu toward the very edge of the samples. A combination of techniques has therefore demonstrated that H2S deactivation of Cu/ZnO/Al2O3 catalyst bodies occurs via phase transformation of the active Cu/ZnO phase into sulfides and redistribution of these components over the sample instead of Cu active site poisoning by Sads species.

Correlation between Asphaltene Stability in n-Heptane and Crude Oil Composition Revealed with In Situ Chemical Imaging

Five crude oil samples with different physical properties have been studied with respect to asphaltene stability. The attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic imaging approach of n-heptane-induced precipitation has been used to monitor crude oil behaviour under dilution with a flocculation agent. For each sample, the dynamics of asphaltene precipitation has been observed by applying this chemical imaging method. Based on these data, the stability of crude oil samples has been compared and the correlation between asphaltene stability and crude oil properties has been proposed.

Development of a Raman chemical imaging detection method for authenticating skim milk powder

This research developed a Raman chemical imaging method for detecting multiple adulterants in skim milk powder. Ammonium sulfate, dicyandiamide, melamine, and urea were mixed into the milk powder as chemical adulterants in the concentration range of 0.1–5.0 %. A Raman imaging system with a 785-nm laser was used to acquire hyperspectral images in the wavenumber range of 102–2,538 cm−1 for a 25 × 25 mm2 area of each mixture. A polynomial curve-fitting method was used to correct for the fluorescence background in the Raman images. An image classification method was developed based on single-band fluorescence-free images at unique Raman peaks of the adulterants. Raman chemical images were created to visualize identification and distribution of the multiple adulterant particles in the milk powder. A linear relationship was found between adulterant pixel number and adulterant concentration, demonstrating the potential of this Raman chemical imaging method for quantitative analysis of adulterants in the milk powder.

Quantifying nanoscale biochemical heterogeneity in human epithelial cancer cells using combined AFM and PTIR absorption nanoimaging

Subcellular chemical heterogeneity plays a key role in cell organization and function. However the biomechanics underlying the structure-function relationship is governed by cell substructures which are poorly resolved using conventional chemical imaging methods. To date, advances in sub-diffraction limited infrared (IR) nanoscopy have permitted intracellular chemical mapping. In this work we report how image analysis applied to a combination of IR absorption nanoimaging and topographic data permits quantification of chemical complexity at the nanoscale, enabling the analysis of biochemical heterogeneity in mammalian cancer cells on the scale of subcellular features.

Hard X‐ray Spectroscopic Nano‐Imaging of Hierarchical Functional Materials at Work

Heterogeneous catalysts often consist of an active metal (oxide) in close contact with a support material and various promoter elements. Although macroscopic properties, such as activity, selectivity and stability, can be assessed with catalyst performance testing, the development of relevant, preferably quantitative structure-performance relationships require the use of advanced characterisation methods. Spectroscopic imaging in the hard X-ray region with nanometer-scale resolution has very recently emerged as a powerful approach to elucidate the hierarchical structure and related chemistry of catalytic solids in action under realistic reaction conditions. This X-ray-based chemical imaging method benefits from the combination of high resolution (∼30 nm) with large X-ray penetration and depth of focus, and the possibility for probing large areas with mosaic imaging. These capabilities make it possible to obtain spatial and temporal information on chemical changes in catalytic solids as well as a wide variety of other functional materials, such as fuel cells and batteries, in their full complexity and integrity. In this concept article we provide details on the method and setup of full-field hard X-ray spectroscopic imaging, illustrate its potential for spatiotemporal chemical imaging by making use of recent showcases, outline the pros and cons of this experimental approach and discuss some future directions for hierarchical functional materials research.

Impact of fasting on human brain acid‐base homeostasis using natural abundance 13C and 31P MRS

To use (13) C magnetic resonance spectroscopy (MRS) and (31) P MRS to develop a direct assay for regional [HCO3-] in the human brain and to define brain pH and physiological response of [HCO3-] to fasting. Seven healthy subjects underwent MRS examinations on a 1.5T MRI scanner. Subjects were well fed with repeated examinations performed after 4 and 12 hours of fasting. Proton noise decoupling (13) C MRS were acquired using pulse and acquired acquisition while (31) P MRS were acquired using a 2D chemical shift imaging method with relaxation time (TR) of 2 seconds. Fasting brain bicarbonate concentrations (6.7 ± 2.5 mM for 12-hour fasting, P = 0.002 and 8.3 ± 2.1 mM for 4-hour fasting, P = 0.015) are significantly reduced compared to fed state (11.6 ± 1.3 mM). However, no significant difference in brain pH was observed, confirming the critical role of pCO2 in intracerebral pH homeostasis. We demonstrated that the intracellular HCO3- in human brain is readily modified by diet but appears to have no measurable effect on cerebral pH. Natural abundance (13) C can provide useful information relevant to human brain pH homeostasis by providing information for HCO3-.

Nanoscale infrared absorption imaging permits non-destructive intracellular photosensitizer localization for subcellular uptake analysis

The most immediate biological and medical advantages of therapeutic agent localization on the nanoscale arise from the increased understanding of targeted delivery, selectivity and intracellular distribution that are gained by imaging at the resolution scale of individual nanovectors and therapeutic agents themselves. This paper reports on the use of a nanoscale resolution chemical imaging method, infrared (IR) nanospectral absorption imaging, used to map the subcellular localization of a photoactive therapeutic agent - toluidine blue-conjugated gold nanoparticles (TBO) within nanoscale subsections of single colon adenocarcinoma cells. By comparison of photosensitizer distribution with diffraction limited optical imaging, the benefits of IR nanospectral localization are highlighted and the spatial and spectral accuracy of the non-destructive IR imaging method is confirmed. IR spectral ratio imaging is presented as a means to map intracellular nanoparticle density at sub 50 nm lateral resolution with IR nanospectroscopy enabling distinction of nanoparticle seeded cells from a control group with 95% confidence. In this way we illustrate that IR absorption nanoimaging combined with IR point source data does not only yield intracellular drug detection on the order of nanometres, but also permits extension of the AFM-IR technique from subcellular analysis up to studies of cell numbers that are statistically significant.

ATR-FTIR spectroscopic imaging: recent advances and applications to biological systems

Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic imaging is a highly versatile, label free and non-destructive chemical imaging method which can be applied to study a wide range of samples and systems. This review summarises some of the recent advances and applications of this imaging method in the area of biomedical studies, including examples of section of aorta, skin tissue and live cells. Two of the major advantages of measuring in ATR mode are the opportunity to measure samples that absorb strongly in the IR spectrum, such as aqueous systems, without significant sample preparation and the ability to increase the spatial resolution of the measured image. The implications of these advantages as well as some limitations of this imaging approach are discussed and a brief outlook at some of the possible future developments in this area is provided.

Chemical Shift MR Imaging Methods for the Quantification of Transcatheter Lipiodol Delivery to the Liver: Preclinical Feasibility Studies in a Rodent Model

To demonstrate the feasibility of using chemical shift magnetic resonance (MR) imaging fat-water separation methods for quantitative estimation of transcatheter lipiodol delivery to liver tissues. Studies were performed in accordance with institutional Animal Care and Use Committee guidelines. Proton nuclear MR spectroscopy was first performed to identify lipiodol spectral peaks and relative amplitudes. Next, phantoms were constructed with increasing lipiodol-water volume fractions. A multiecho chemical shift-based fat-water separation method was used to quantify lipiodol concentration within each phantom. Six rats served as controls; 18 rats underwent catheterization with digital subtraction angiography guidance for intraportal infusion of a 15%, 30%, or 50% by volume lipiodol-saline mixture. MR imaging measurements were used to quantify lipiodol delivery to each rat liver. Lipiodol concentration maps were reconstructed by using both single-peak and multipeak chemical shift models. Intraclass and Spearman correlation coefficients were calculated for statistical comparison of MR imaging-based lipiodol concentration and volume measurements to reference standards (known lipiodol phantom compositions and the infused lipiodol dose during rat studies). Both single-peak and multipeak measurements were well correlated to phantom lipiodol concentrations (r(2) > 0.99). Lipiodol volume measurements were progressively and significantly higher when comparing between animals receiving different doses (P < .05 for each comparison). MR imaging-based lipiodol volume measurements strongly correlated with infused dose (intraclass correlation coefficients > 0.93, P < .001) with both single- and multipeak approaches. Chemical shift MR imaging fat-water separation methods can be used for quantitative measurements of lipiodol delivery to liver tissues.

Model‐based mapping of fat unsaturation and chain length by chemical shift imaging—phantom validation and in vivo feasibility

Knowledge about the triglyceride (fat) (1)H spectrum enables quantitative determination of several triglyceride characteristics. This work describes a model-based chemical shift imaging method that separates water and fat signal and provides maps of three triglyceride quantities: fatty acid carbon chain length, unsaturation degree, and polyunsaturation degree. The method was validated by imaging a phantom containing 10 different oils using 1.5 and 3.0 T clinical scanners, with gas-liquid chromatography as reference. Repeated acquisitions demonstrated high reproducibility of the method. Statistical tests of correlation and linear regression were performed to examine the accuracy of the method. Significant correlation was found at both field strengths for all three quantities, and high correlation (r(2) > 0.95) was found for measuring unsaturation degree and polyunsaturation degree. Feasibility of the method for in vivo imaging of the thigh was demonstrated at both field strengths. The estimates of unsaturation degree and polyunsaturation degree in subcutaneous adipose tissue were in agreement with literature values, while chain length appeared over estimated. The method has potential use in large-scale cross-sectional and longitudinal studies of triglyceride composition, and its relation to diet and various diseases.

New Entities in Dermatology

Dermatology is a rapidly developing medical field, in which too many new advances in terms of diagnosis and therapy have occurred within the last several years. Technological progression of chemical science and imaging methods as well as new tools have made it possible to expose the mysterious aspects of diseases. Therefore, novel dermatologic entities have been described day by day. In this article we decided to search new entities reported electronically in Pubmed and EBSCO indexes in the last decade after year 2002. Twenty-six new entities were found out after our investigation. In this review, the reported entities have been classified according to the sections of dermatologic disorders. We think that this article would help to update the knowledge of dermatologists about new concepts.

Chemical element imaging for speleothem geochemistry: Application to a uranium-bearing corallite with aragonite diagenesis to opal (Eastern Siberia, Russia)

Two complementary image-based microanalysis methods, digital autoradiography of radioactive elements and X-ray fluorescence microspectroscopy (micro-XRF), were used to study the geochemistry of a speleothem from Eastern Siberia. Our objective was to show the interest of these micro-chemical methods to investigate the distribution of U and some other elements as Ca, Sr, and Si in speleothems. The sample studied was a corallite concretion that formed slowly by the precipitation of minerals from moisture that had condensed underground. Polished sections of the sample revealed alternating laminas of gray calcite and white aragonite. The concretion, which is older than 400Kyr (U/Th-TIMS), showed no signs of detrital contamination (230Th/232Th>10,000). Digital autoradiography and XRF analyses indicated exceptionally high uranium contents, ranging from 3–10 to more than 1300μg∙g−1 in different areas of the sample. Element maps for calcium (Ca), uranium (U), strontium (Sr) and silicon (Si) showed inverse correlations between Ca and U and between Ca and Si, but there is a strong correlation between Si and U. Under the optical microscope, the low Ca appears as corrosion voids, which were found to contain uranium-enriched amorphous silica replacing areas of aragonite and, in some cases, calcite. This postgenetic amorphous and uraniferous silica is composed of two kinds of opal: opal A formed by large microspheres of 30–40μm in diameter and a gray opal CT with irregular lepispheres. This late opal, dated around 385–412Kyr, is probably due to a special volcanic event formed by uraniferous glass ashes easily soluble by meteoric waters, as suggested by the presence of volcanic suite in the fine fraction of the opal. Opal precipitated after speleothem crystallization by evaporation or cryogenic supersaturation. The study of this exceptional concretion shows the value of direct chemical imaging methods, as they easily revealed the presence and distribution of U in the concretion, and allowed an unusual case of opal diagenesis in a carbonate speleothem to be described. Given the value of speleothems as geo-chronometers and recorders of environmental changes at different time scales, from season to isotopic stage, this methodology opens new perspectives in understanding the geochemical system and consequently the validity of radiometric datings, U/Th and U/Pb, especially in speleothem samples.

Super-resolution surface mapping using the trajectories of molecular probes

The surface characterization of 'soft' materials presents a significant scientific challenge, particularly under 'wet' in situ conditions where a wide variety of non-covalent interactions may be relevant. Here we introduce a new chemical imaging method, MAPT (mapping using accumulated probe trajectories) that generates images of surface interactions by distributing different aspects of molecular probe trajectories into distinct locations and then combining many trajectories to generate spatial maps. The maps are super-resolution in nature, because they are accumulated from highly localized single-molecule observations. Unlike other super-resolution techniques, which report only photon or point counts, our analysis generates spatial maps of physical quantities (adsorption rate, desorption probability, local surface diffusion coefficient, surface coverage/occupancy) that are directly associated with the molecular interactions between the probe molecule and the surface. We demonstrate the feasibility of this characterization using a surface patterned with various degrees of hydrophobicity.

Presurgical Localization of Parathyroid Adenomas with Magnetic Resonance Imaging at 3.0 T: An Adjunct Method to Supplement Traditional Imaging

To investigate the use of a chemical shift-based water-fat separation magnetic resonance imaging (MRI) method, and time-resolved contrast-enhanced MRI at 3 T for improved presurgical localization of parathyroid adenomas. Twenty-five patients with primary hyperparathyroidism were prospectively enrolled. Patients underwent MRI, which was reviewed by two experienced neuroradiologists who were blinded to Tc-99m sestamibi imaging and operative results. Overall, MRI detected 16 adenomas in 25 patients (sensitivity 64%, positive predictive value 67%), while sestamibi detected 18 of 25 adenomas (sensitivity 72%, positive predictive value 90%). Importantly, MRI was able to detect adenomas in four (57%) of the seven patients whose disease was missed by sestamibi analysis. MRI demonstrated excellent image quality and fat suppression by using a chemical shift-based water-fat separation technique. The time-resolved MRI was considered to be less helpful, although in some cases it was indispensable. MRI is an excellent adjunct for preoperative parathyroid localization. The advent of improved fat suppression techniques in the neck, including chemical shift-based water-fat separation, is critical to its utility. Although time-resolved MRI was not always helpful, it was crucial in certain cases. It may prove to be more useful with the development of faster scanning techniques.

Analysis of pharmaceutical pellets: An approach using near-infrared chemical imaging

Pharmaceutical pellets are spherical or nearly spherical multi-unit dosage forms designed to optimize pharmacokinetics and pharmacodynamics features of drug release. The distribution of the pharmaceutical ingredients in the layers and core is a very important parameter for appropriate drug release, especially for pellets manufactured by the process of layer gain. Physical aspects of the sample are normally evaluated by Scanning Electron Microscopy (SEM), but it is in many cases unsuitable to provide conclusive chemical information about the distribution of the pharmaceutical ingredients in both layers and core. On the other hand, methods based on spectroscopic imaging can be very promising for this purpose. In this work, a Near-Infrared Chemical Imaging (NIR-CI) method was developed and applied to the analysis of diclophenac sodium pellets. Since all the compounds present in the sample were known in advance, Classical Least Squares (CLS) was used for calculations. The results have shown that the method was capable of providing chemical information about the distribution of the active ingredient and excipients in the core and coating layers and therefore can be complementary to SEM for the pharmaceutical development of pellets.